This invention relates to a wooden suspended ceiling system, and more specifically to the grid system of such a wooden suspended ceiling system for supporting ceiling panels, lighting fixtures, or air vents in a suspended ceiling.
Generally, in modern office buildings, each floor of the building, prior to being subdivided and occupied by tenants, consists of a finished floor and a continuous, suspended ceiling having a plurality of fluorescent (or other) lighting fixtures spaced in the ceiling at desired intervals. Additionally, heating, ventilating, and air conditioning (HVAC) outlets are provided at desired spaced locations within the suspended ceiling system. The suspended ceiling typically comprises a metal grid consisting of longitudinal parallel runners spaced apart from one another a desired distance, separated by cross members at desired intervals with the runners and cross members being perpendicular to one another and defining a plurality of generally rectangular openings between the perpendicular runners and cross members. These openings are of a standardized size (e.g., two feet.times.two feet) such that modularized ceiling panels, lighting fixtures, or ventilation outlets may be dropped in place within the openings of the grid systems at desired locations and supported by the ceiling grid system. Typically, the ceiling grid system is suspended below the roof or floor immediately thereabove by means of suspension wires interconnecting the grid system to the structure thereabove, with the suspension wires being adjusted in such manner so as to ensure that the ceiling is suspended in a level position at a desired height above the floor below. Typically, in modern commercial buildings, a sufficient space is provided between the suspended ceiling and the structure thereabove so as to permit HVAC ducts, electrical wiring, plumbing pipes, etc., to readily be mounted between the suspended ceiling and the floor or ceiling structure thereabove.
Upon constructing a new office building, once a tenant leases or occupies the space, partitions within the building, typically consisting of vertical metal studs faced with dry wall sheathing on each side thereof, are erected on the floor at desired locations and are secured to the floor so as to sub-divide the space into a desired interior arrangement. Suitable doors and other fixtures are incorporated in the wall partitions. However, the partitions are typically not connected to the suspended ceiling and, in fact, the suspended ceiling may, at least in part, rest or bear on the upper surfaces of the partitions. In the event one wishes to change the floor plan of the building, it is a relatively simple and inexpensive matter to remove the partitions and to erect others without having any effect on the suspended ceiling system. Oftentimes, it is a relatively easy matter to relocate lighting fixtures and air vents within the ceiling grid structure so that rooms defined by the subsequently erected wall partitions serve desired occupied areas or rooms within the building.
Reference may be made to such patents as U.S. Pat. Nos. as 2,971,617, 2,994,113, 3,013,644, 3,329,387, 3,385,021, 3,783,771, 3,785,110, 4,019,300, 4,040,758, and 4,047,348, which show a variety of conventional prior art suspended ceiling systems utilizing intersecting, perpendicular metal grid members. While these prior art suspended ceiling systems worked well for their intended purposes, and while they were of rigid construction and were relatively easy to interconnect with one another, the bottom faces of the grid members were typically readily viewable from below by occupants within a room.
Typically, the ceiling panels utilized with such typical prior art metal grid systems were of a fibrous composition material, and were so manufactured as to have a finished bottom face with flanges or shoulders extending outwardly from the periphery of the ceiling panel, and with the bottom face of the ceiling panel being positioned below these outwardly extending flanges such that when the ceiling panel is dropped into position from above within a respective grid opening in the metal grid suspended ceiling system, the ceiling panel would be readily received and supported by the intersection grid members with the bottom faces of all the ceiling panels being substantially coplanar, and with the bottom faces of the grid members appearing as batt members separating adjacent ceiling panels.
It had long been recognized in many commercial buildings that the appearance of such utilitarian ceiling systems utilizing metallic grids resulted in a highly practical ceiling system, but did not enhance the appearance of a room, particularly where an upscale interior finish was desired.
In an effort to enhance the appearance of such metal suspended ceiling grid systems, simulated wood grain risers or grid members were utilized (i.e., metal grid members having a wood grain finish imprinted thereon or adhered thereto was utilized), as shown in U.S. Pat. No. 3,583,119.
It was also known to utilize imitation wood beams, as shown in U.S. Pat. No. 3,557,506, which were fastened to the bottom portions of the conventional metal grid suspended ceiling systems.
Still further, as shown in U.S. Pat. Nos. 4,454,700, 4,281,498, 4,367,616, 4,452,021, 4,464,876, and 4,525,971, a variety of wood beam suspended ceiling systems have been proposed. Typically, like metal grid suspended ceiling systems, these prior art wooden suspended ceiling systems utilized elongate runners with perpendicular cross members. However, these wooden suspended ceiling systems required a variety of metallic clips or other, separate fastening members for rigidly interconnecting the cross members to the runners. Typically, these connecting members were made of metal and were required, either in the field during installation or at the factory prior to installation, to be separately attached to the cross members and to the runners.